Total synthesis of steroids. Part 2. Preparation of C-10 methylated steroids. Regio-and stereocontrol in a diene addition to methyl Z-2-methyl-4-oxo-2-pentenoate

J Das, RA Dickinson, M Kakushima…

Index: Das, Jangabandhu; Dickinson, Robert A.; Kakushima, Masatoshi; Kingston, Gregory M.; Reid, Gary R.; et al. Canadian Journal of Chemistry, 1984 , vol. 62, p. 1103 - 1111

Full Text: HTML

Citation Number: 17

Abstract

A twelve-step total synthesis of 14-epi-androsta-4, 9 (11), 15-triene-3, 17-dione from methyl vinyl ketone, 2-methylcyclo-hexane-1, 3-dione, acetylene, and methyl Z-2-methyl-4-oxo-2- pentenoate is described. Crucial steps include a stereo-and regio-selective diene addition, an efficient formation of ring D by C-acylation of an acetyl group, and a selective bromine substitution at C-15 in a 15, 17-dione intermediate. The stereo-and regioselectivity of the ...